Grinding wheel and holder therefor



H. c. BEACH 1,710,528

GRINDING WHEEL AND HOLDER THEREFOR April 23, 1929.

2 SheetsSheet 1 Filed June 23, 1925 April 23, 1929. c, BEACH 1,710,528

GRINDING WHEEL AND HOLDER THEREFOR Filed. June 25, 1925 2 Sheets-Sheet; 2

2 iif i ik-ii: 1

Patented Apr. 23, 1929.

UNITED STATES 1 1,710,528 PATENT OFFICE.

HOBART C. BEACH, OF COVINGTON, KENTUCKY, ASSIGNOR '10 THE CARBORUNDUM COMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF PENNSYLVANIA.

GRINDING WHEEL AND HOLDER THEREFOR.

Application filed June 23, 1925. Serial No. 39,011.

For grinding certain classes of work, such as the inside surfaces of bath tubs, to prepare them for enameling, and similar castings, for example, the grinding wheel is mounted on the end of a flexible operating shaft, in order to enable the operator to move the wheel from point to point, and both the face and the edge of the grinding wheel are used as grinding surfaces. This work isvery hard on the grinding wheel and causes it to wear away rapidly, necessitating frequent replacement ofwheels. Heretofore such wheels have been formed cup-shaped and the operating shaft extended through the bottom of the cup and the wheel secured thereto, by means of a nut engaging the threaded end of the shaft inside the hollow cup. With this method of mounting it was impossible to wear down the wheel lower than the nut, so that the stub to be thrown away constituted a considerable portion of the wheel. Also, there was considerable danger to the operator by reason of the liability of the rapidly rotating wheel cracking and then flying to pieces, as this method of mounting did not afford any support for the cracked tending to prevent it from flying to pieces.

The present invention is designed to overcome the above objectionable features inher: ent in the former method of mounting grinding wheels of this character. Itprovides a method of mounting wherein the wheel is more firn' ly held by the holder and wherein a much greater proportion of the Wheel is available for grinding and hence the stub to be thrown away is much smaller than in the old method of mounting. Moreover, my improved method of mounting tends to prevent explosion of the wheel in case it becomes cracked during operation thereof.

In the accompanying drawings:

Figure 1 is a perspective view of the grinding wheel and its holder connected to a flexible operating shaft and embodying a preferred form of my invention; Figure 2 is a sectional view of the grinding wheel and its holder; I

Figure 3 is a plan View of the clamping jaws of the holder; 1

Figure 4 is a plan view of the center member of the holder;

Figure 4 is adetail View of the grinding wheel when Worn thin and of the holder;

Figure 5 ma plan View of a slightly modiwheel fied form of grinding wheel and holder embodying my invention; and

Figure 6 is a transverse sectional view taken on the line VIVI of Figure 5. In the construction shown inFigures 1 to 4, inclusive, the grinding wheel 2 has a central bore 3 and has a reduced hub portion 4 proyecting from one end face thereof and havlng an undercut peripheral wall 5.

The holder comprises a cylindrical center 6, the lower portion 7 of which has an enlargedbore to receive the end of the flexible operating shaft 8. The upper portion of the center may have a central hole 9 therethrough to receive a suitable fastening element for securing the operating shaft to the center. Theportion 7 is exteriorly screw-threaded to receive a pair of lock nuts 10 adapted to be operated by a spanner wrench. The center 6 has a flange 11 at its upper end adapted to lie beneath the end face of the hub portion 4 of the wheel. This flan e has an annular rib 12. adapted to enter the bore of the wheel and center the same on the flange. The flange 11 and rib 12 have a plurality of radial slots 13 therein for a purpose which will presently be described.

Adapted to engage the hub portion 4 is a clamping member 14 formed in a plurality of segments 15. This clamping member is adapted to surround the upper portion of the center 6 and the segments 15 are formed with portions 16 forming a clamping ring having an inclined inner face 17 for engagement with the underqut peripheral wall 5 of the hub portlon 4. This ring has a flange 16 at its upper edge adapted to bear against the end hub portion 4 projects so as to form a support for the wheel as it wears down. For example, when the wheel wears down as shown in Figure 4, a thin portion is left which would breakoff if unsupported With the clamping member acting as a support back of this porface of thegrinding wheel from which the tion, however, it is possible to wear it thinner with safety and thus get more wear out of the wheel. Preferably a ring 16 of blotting paper is put between the flange 16 and the surface of the wheel, as indicated in Fig ure 4. The segments 15 also have upwardly projecting pins 18 adapted to enter the radial slots 13 of the center 6. The innerportions of the segments 15 which carry the pins 18 are 7 of reduced thickness so as to provide recesses clamping segments by the lock nuts 10,

whereby the clamping segments are adapted to be forced into firm engagement with the hub portion of the grinding wheel.

It will be apparent that by this construction the grinding wheel is firmly held by the holder and that the wheel can be worn down almost, if not quite, to the hub portion, which latter forms a relatively small proportion of the. wheel. Furthermore, since the portions 16 of the clamping segments 15 surround the hub portion 4:, these clamping segments tend to hold the wheel together in case it becomes cracked in service, thereby greatly lessening the danger of the wheel exploding.

In the modified construction shown in Figures 5 and 6, the grinding wheel 2 has a hub portion 4 having an inclined inner peripheral surface 23 and a vertical outer peripheral surface 24. The holder comprises a centering nut 25 which is adapted to engage the screw-threaded end 26 of an operating shaft 27. This nut has a flange 28 at its upper end having an inclined peripheral edge 29 for engagement with the inclined inner peripheral surface 23 of the hub 4 of the grinding wheel. This flange, has openings 30 therein whereby the nut is adapted to be turned by a suitable tool. The lower portion of the nut is exteriorl screw-threaded, whereby the nut is adapte to be screwed into the screw-threaded bore of a clamping plate 31. The lower face of this clamping plate is engaged by the upper face of an enlargement 32 on the operating shaft 27 and the 11 per face of the plate is adapted to engage the face .of the hub portion 4!. The clamping plate has a flange 33 adapted to surround the hub portion 4 and to make a'sliding fit with the vertical outer peripheral wall 24 thereof.

'It will be seen that by tightening the nut 28,

the hub portion 4* will be firmly clamped by the holder. While the flange 33 in the construction shown in Figures 5 and 6 does not have any clamping function, it will tend to hold the wheel together in case it becomes cracked in service.

While I have shown and described twp preferred embodiments of my invention, it will be understood that the invention is not limited to'its illustrated embodiments, but that it may be otherwise embodied within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In a wheel assembly, a bonded abrasive grinding wheel having a reduced hub portion on one face thereof, a series of radially arranged elements cooperating with the periphery of the hub portion and having inclined peripheral surfaces thereon, a central member about which said radially arranged elements are arranged, a disk on the central member having a flange thereon slidably embracing the inclined peripheral surfaces of said radially arranged elements, and means threaded on the central member for holding the disk in cooperative engagement with said segmental members.

2. In a grinding wheel assembly, a bonded abrasive wheel having a reduced holder portion on one face thereof, a hub having a central member cooperating with the end of the hub portion of the wheel, a series of radially disposed elements arranged about the central member and slidable thereon having lugs for cooperation with the periphery of the hub portion of the wheel, and having smooth inclined peripheral surfaces thereon, a disk on the central member having an inclined flange slightly embracing the inclined peripheral surfaces of said radially disposed elements for holding them in clamping relation with the hub portion of the wheel, and means on the central member for holding the disk in cooperative engagement with said members.

.3. In combination, a bonded abrasive grinding wheel having a central bore and a reduced hub portion projecting from one end face' thereof, and a cylindrical center member having a flange at one end .for engagement with the end face of said hub portion and a rib adapted, to enter said bore for.

centering said wheel on said flange, said flange having a plurality of radial slots therein, a plurality of clamping segments having means adapted to project into said slots and having flanges adapted to engage the outer peripheral surface of said hub portion and follower means adapted to force said clamping segments into clamping engagement with said hub portion, substantially as described.

In testimony whereof I have hereunto set my hand.

' HOBART C. BEACH. 

